An image sensor (or imager) generally refers to the part of an image-capturing device (e.g., a camera) that can detect and convey the information required to form an image. In a digital camera, the image sensor can typically be a silicon semiconductor on which images are captured. Structurally, the sensor can be composed of an array of photosensitive diodes (i.e., photosites) that capture photons and converts them to electrons. The buildup of electrons in each photosite can be converted to an electronic signal (e.g., a voltage), which can in turn be converted to digital data representing a picture element or pixel. These elements or pixels can then be used for assembling the final image. The final image can be stored in the camera's memory and retrieved to be viewed on a display and/or further manipulated.
Ideally, a well-designed image sensor allows the camera to have a relatively high-speed frame rate that enables the camera to capture a larger number of images within a short period of time and, at the same time, uphold image quality by minimizing the amount of undesirable effects such as motion artifacts in the result images.